Vulcanizing equipment



Aug- 30 1949- M. J. DAHIM ET AL 2,480,714

VULCANIZING EQUIPMENT 2 Shee'ts-Sheet 1 Filed April 16, 1947 Aug. 30, 1949.

Filed April 16, 19.47

M. J. -DAHEIM ET AL 2,480,714A

yVULC'ANIZING EQUIPMENT 2 Sheets-Sheet 2 Patented Aug. 30, 1949 2,480,714 vULcANIziNG EQUIPMENT Mathias J. Daheim and Frank L. Finn,

Minneapolis, Minn.

Application April 16, 1947, Serial No. 741,792

2 Claims.

Oui` invention relates to vulcanizing equipment and is designed primarily for applying patches to inner tubes of pneumatic tires.

The primary object of our invention is the provision of vulcanizing equipment, incorporating a bed plate, a bridge beam, a pressure shoe interposed between the bed plate and the bridge beam and carried by the latter, and means for clamping said bridge beam to vsaid bed plate, in which the pressure shoe is permitted to rock in lbut one plane.

Another important object of our invention is the provision of such a structure having an elongated pressure shoe, which is mounted on said bridge beam by a head and socket connection which permits rocking movements thereof, under set conditions, only in a vertical plane longiudinally ofthe bridge beam. Under the above novel arrangement, the pressure shoe Ais maintained at all times in parallel relationship to the bed plate, irrespective of the thickness of the material placed therebetween.

It is affurther object of our invention to provide a pressure pad intermediate the bed plate and the pressure shoe, which is made from rubber-like resilient material capable of being displaced suiciently to compensate for the dilferences in thickness in the material being vulcanized, with the result that a uniform' degree of heat is brought to bear upon all of the tube underlying the pressure shoe.

Another object of our invention is the provision of a novel combination of elements including a pressure shoe havinga soleplate with a central recess therein adapted to receive a plurality of different shaped inserts, whereby to accommodate diiferent shapes and sizes of valve stems for vulcanization.

The above and still further objects of our invention will become apparent from the following detailed specification, appended claims, and attached drawings.

Referring to the drawings, wherein like characters indicate like parts throughout the several views:

Fig. 1 is aside elevation, illustrating my device in vulcanizing position on an inner tube, with some parts being broken away and some parts being shown in section;

Fig. 2 is a vertical section, taken on the line 2 2 of Fig. 1, on an enlarged scale and with some parts being broken away;

Fig. 3 is a View corresponding to Fig. 2` showing a slightly dilerent use of the equipment;

Fig. 4 is a view corresponding to Fig. 3, but illustratng astill diierent use of the equipment; and

Fig. 5 is an axial section in perspective of one of the soleplate inserts, some parts being broken away.

Referring with greater particularity to the drawings, the numeral I indicates a bed plate, preferably formed from Vcast iron or the like and formed on its upper face with a circular recess 2, which is adapted to snugly receive a resilient displaceable pressure pad preferably formed from cured rubber-like material. A bridge beam V1S, shown as being arcuate in form, has one end horizontally pivotally secured to the bed plate l by a hinge pin '5. Adjacent its opposite end, the bridge beam is provided with a segmental recess S in which is seated the rounded head l of a clamping lever A3. Eccentrically pivoted, as indi-- cated at 9, is the upper end of a clamping stud Ii), which extends downwardly through an opening il in the outer end of a bridge beam 4 `and into yan outwardly opening :slot l2 in the end of the bed plate I. At its threaded lower end, the clamping stud I0 is equipped with van ladjustable clamping nut I3. The clamping nut I3 is equipped with a circumferential flange I4 that is adapted, under downward clamping movements of 'the clamping lever B, to engage `shoulders I 5 in the slot I2.

In 'its central portion, the bridge -beam 4 is provided with a downwardly-opening cylindrical socket i6, which is adapted to receive a head I'I of an elongated'rectangular pressure shoe i8 interposed between the bridge -beam 4 and the'bed plate i. It will be noted, particularly with reference to Figs. `l and 2, that the head I1 is arcuate in shape transversely of the pressure shoe I8, but is flat in a direction longitudinally of the pressure shoe I8 for a purpose which will hereinafter become apparent. Furthermore, the ydepth of the downwardly-opening cylindrical socket I6, as compared to the thickness of the head I'I, is such as t0 permit limited rocking movements of the pressure shoe I3 in -a direction transversely of said pressure shoe. A split retaining collar I9 is secured to the under side of the bridge beam `4, by means of screws or thelike 20, and supports the head I1 within the cylindrical socket I6 when the bridge beam is in its raised dotted line position of Fig. l.

The pressure shoe I 8 is of a hollow box-like construction vand contains a heating element, not shown, preferably electrical in nature and supplied with electrical current through electrical wiring 2l. At its base, the pressure shoe I8 is provided with a soleplate 22 having a central recess v23, preferably circular in form. A circular soleplate insert 24 is adapted to be received within the recess 23 and may 'be held therein by means of a 'face plate 25 having resilient hooked ends .26, which are adapted to t into notches 2'! in opposite side or end walls of the pressure shoe I8.

The structure illustrated vin Fig. 2 is specically designed for use in vulcanizing of patches on inner tubes, where the repair is remote from the valve stem. When it is desired to utilize my novel 28 (see Figs. 3 and 5) is inserted into the central recess 23. It will be noted that the insert 28 has a central opening 29, which is aligned with axially aligned openings 30 and 3I in the pressure shoe I8 and in the head I1 thereof and 32 in the bridge beam 4. Thus, the aligned openings 29, 30, 3I, and 32 are capable oi receiving a valve stem :I: of any length.

When it is desired to vulcanize a new valve stem to an inner tube, a soleplate insert similar to insert 33 (see Fig. 4) is utilized. It will be observed that the insert 33 diiers from the insert 28 in that it has a circumferential ange 34, which extends below the soleplate 22, thereby limiting heat and pressure to the area of the tube immediately underlying the insert 33.

Operation of clamping mechanism When an inner tube has been placed in position for vulcanization, as indicated in Figs. 1 to 4 inclusive, the clamping nut I3 is screwed upwardly on the threaded end of clamping stud I8 until the ange I4 thereof engages the shoulders I5 in the slot I2. Thereafter, the necessary degree of pressure between the shoe I8 and the inner tube, indicated by the letter y, is quickly obtained by depressing the eccentrically pivoted clamping lever 8 to the full line position indicated in Fig. l. After vulcanization, the lever 8 is elevated to the dotted line position shown by Fig. 1 and clamping nut I3 is swung outwardly of the slot I2 at which position, the bridge beam 4 and pressure shoe I8 may be elevated to the dotted line position shown in Fig. l. It will be noted that the ange I4 of the clamping nut I3 is located adjacent one end of the clamping nut I3, whereby to allow the clamping nut I3 to be reversed on the clamping stud I8 to accommodate greater thicknesses of material between the pressure shoe I8 and the bed plate l.

Operation of the pressure shoe It will be observed that the normal position of the elongated pressure shoe I8 is transversely of the bridge beam 4. In this position, the pressure shoe I8 is permitted to rock in a vertical plane parallel to the bridge beam 4 and transversely to the pressure shoe I8, but is prevented from rocking in a vertical plane transversely of bridge beam, to compensate for varying elevations of the bridge beam due to varying thicknesses of material, parallelism between the soleplate 22 of the pressure shoe I8 and the bed plate I is maintained at all times, irrespective of whether the thickest portion of the material being vulcanized directly underlies the socket or not. This,

or" course, means that the thickest material gets the greatest pressure. However, to prevent too great a pressure being appliedinany given point beneath the pressure shoe I8, we provide the thick cured rubber pressure pad, which is capable of being displaced suiiciently to compensate for the uneven pressures due to the uneven thicknesses of the material being vulcanized.

While we have disclosed a preferred embodiment of our invention as provided by section 4888 of the United States Statutes, it should be understood that the same is subject to modication without departure from the scope of the appended claims.

What we claim is:

l. In a device of the class described, a bed plate, a bridge beam, means mounting one end portion of the bridge beam for pivotal movements with respect to the bed plate on a horizontal axis, a pressure shoe interposed between the intermediate portion of the bridge beam and the bed plate and carried by the former by means of a joint permitting rotary movements of said shoe but allowing lateral swinging movements thereof in only one plane, and clamping means cooperating with the extended other end of the bridge beam.

2. In a device of the class described, a bed plate, a bridge beam element, means mounting one end portion of the bridge beam element for pivotal movements with respect to the bed plate on a horizontal axis, an elongated pressure shoe element interposed between the intermediate portion of the bridge beam element and the bed plate, a connection between the intermediate portion of said bridge beam element and the intermediate portion of the pressure shoe element comprising a socket bore in one of said elements y jacent end of the head being arcuate in one dithe bridge beam 4 and longitudinally of the pressure shoe I8 by virtue of the fact that the head l I 'I is rounded in one direction and straight in the other (see Figs. 1 and 2).

In prior art structures, it has been common practice to secure the pressure shoe to the bridge beam by means of a ball and socket joint, which permits rocking of the shoe in ant7 direction. The result of this type of mounting was that, where the thickest portion of the material being vulcanized did not directly underly the ball and socket connection, the pressure shoe was tilted with respect to the bed plate and consequently brought curing heat and pressure to bear only upon one side of the raised or thick portion.

In our novel arrangement, wherein the pressure shoe I8 is mounted for rocking movements only in a vertical plane longitudinally of the rection and being straight and parallel to the at end of the said socket end in the other direction, and means confining said head within said socket, whereby the shoe is permitted unlimited rotary movements but is restrained from lateral swinging movements except in one plane.

MATHIAS J. DAI-IEIM. FRANK L. FINN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

